Polishing machine work piece holder

ABSTRACT

A work piece holder is provided for use in a polishing machine. The work piece holder has a frame composed of a thermoset material and/or a thermoplastic material. The frame has at least one cavity for receiving and supporting a work piece to be polished in the polishing machine. A polymer film is permanently affixed in the at least one cavity.

FIELD OF THE INVENTION

The present invention is directed to the field of polishing machines, including but not limited to a polishing machine work piece holder.

BACKGROUND OF THE INVENTION

Polishing machines utilize work piece holders to hold and support flat work pieces, sometimes referred to as wafers, such as silicon wafers that are used in the electronics industry.

There is a need for work piece holders that permit production of work pieces having improved precision, as well as having improved service lives.

SUMMARY OF THE INVENTION

In one embodiment, a work piece holder is provided for use in a polishing machine. The work piece holder has a frame composed of a thermoset material and/or a thermoplastic material. The frame has at least one cavity for receiving and supporting a work piece to be polished in the polishing machine. A polymer film is permanently affixed in the at least one cavity.

In another embodiment, a work piece holder is provided for use in a polishing machine. The work piece holder having a frame composed of a thermoset material and/or a thermoplastic material. The frame has at least one cavity for receiving and supporting a work piece to be polished in the polishing machine. A polymer film is permanently affixed in the at least one cavity. The frame includes a first frame portion and a second frame portion, the first frame portion having at least one through opening formed therein.

An advantage of exemplary embodiments is that the work piece holders permit preparation of work pieces having improved precision, as well as having improved service lives.

Other features and advantages of the present invention will be apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a work piece holder according to an embodiment of the disclosure.

FIG. 2 is a section view taken along line 2-2 in FIG. 1.

FIG. 3 is an exploded view of the work piece holder of FIG. 1.

FIG. 4 is a section view taken along line 2-2 in FIG. 1.

FIG. 5 is an exploded view of the work piece holder of FIG. 4.

Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-3, a flat template or work piece holder 10 includes a frame 11 that is releasably secured to a carrier 12 by an adhesive layer 14. Work piece holder 10 can be composed of a thermoset material and/or a thermoplastic material. In one embodiment, a thermoset material can be bonded to and/or surrounded by a thermoplastic material or vice versa to maximize the performance of work piece holder 10. Frame 11 of work piece holder 10 has a plurality of openings 16, such as counterbored openings extending partially through work piece holder 10 to a surface 19. Surfaces 19 of counterbored openings 16 have a depth 17. Each opening 16 and corresponding surface 19 defines a cavity 23.

As further shown in FIG. 2, work piece holder 10 includes a shim or a pad or film layer or film, such as a polymer film 18 having an adhesive layer 21 for permanently affixing polymer film 18 to a corresponding surface 19 of counterbored opening 16. A work piece 20 (FIG. 1) is releasably adhered to polymer film 18, such that work piece 20 is releasably secured to and supported by cavity 23 (FIG. 3). The combined thickness of adhesive layer 21, polymer film 18, and work piece 20 exceeds the thickness of depth 17 of cavity 23 of work piece holder 10. As a result, work piece 20 protrudes beyond the adjacent exposed major face of work piece holder 10. Carrier 12 is adapted to rotate around bearing 22 on spindle 24 for purposes of polishing the exposed surface protruding beyond the adjacent exposed major face of work piece holder 10.

As a result of this work piece holder arrangement, in which polymer film is permanently affixed to the work piece holder, the holding and support of the work piece is improved.

In one embodiment, frame 11 is composed of a thermoset epoxy and/or thermoplastic material(s). In one embodiment, frame 11 is visually transparent, permitting an operator to confirm work pieces 20 are mounted properly in their respective cavities 23 prior to operating the polishing machine. This ability to visually confirm proper work piece mounting is not possible with conventional work piece holders.

As utilized herein, “visually transparent” is intended to indicate a material property of a component sufficiently permitting light to pass through, such that in response to the component being interposed in-line between a vantage point of an observer and an object, the component is viewable by an observer through the component. The term “visually transparent” is intended to include components that are fully visually transparent, partially transparent or translucent or combination thereof

Referring to FIGS. 4 and 5, a flat template or work piece holder 100 is similar to work piece holder 10, except as discussed. Work piece holder 100 includes a frame portion 110 that is releasably secured to a carrier 12 by an adhesive layer 14. Work piece holder 100 can be composed of a thermoset material and/or a thermoplastic material. In one embodiment, a thermoset material can be bonded to and/or surrounded by a thermoplastic material or vice versa to maximize the performance of work piece holder 100. Frame portion 110 of work piece holder 100 is permanently secured to frame portion 112 by an adhesive layer 114. Frame portion 112 has a plurality of openings 16 extending therethrough. Upon assembly of frame portions 110, 112 with adhesive layer 114, openings 16 have a closed end corresponding to the facing surface of frame portion 110. Each opening 16 and corresponding facing surface of frame portion 110, i.e., the closed end of opening 16, defines a cavity 23, such as a counterbored cavity having a depth 17.

As further shown in FIG. 5, work piece holder 100 includes a shim or a pad or film layer or film, such as polymer film 18 having an adhesive layer 21 for permanently affixing polymer film 18 to a corresponding facing surface of frame portion 110 of counterbored opening 16. A work piece 20 (FIG. 4) is releasably adhered to polymer film 18, such that work piece 20 is releasably secured to and supported by cavity 23 of frame portions 110, 112. As shown in FIG. 4, the combined thickness of adhesive layer 21, polymer film 18, and work piece 20 exceeds the thickness of depth 17 of cavity 23 of work piece holder 100. As a result, work piece 20 protrudes beyond the adjacent exposed major face of work piece holder 100. Carrier 12 is adapted to rotate around bearing 22 on spindle 24 for purposes of polishing the exposed surface protruding beyond the adjacent exposed major face of work piece holder 100.

An advantage of this construction is to provide a very tightly controlled cavity depth which provides improved polishing consistency between all work pieces being processed in the work piece holder at one time and in each polishing machine cycle.

Examples of polymer films include thermoplastic polymers polyaryletherketone (PAEK), polyetheretherketone (PEEK), and polyvinylchloride (PVC), as well as an exemplary thermoset polymer G10.

An additional advantage of using polymer film, is that different polymer films can be provided with corresponding work piece holders, resulting in the ability to tailor the work piece holder to provide compatibility with different work piece materials and their corresponding chemical agents which are typically part of the polishing process, including both acidic working or operating environments (e.g., pH<5) as well as basic working or operating environments (e.g., pH>9), including, for example, potassium permanganate (KMnO₄).

Use of polymer film permanently affixed in the cavity of a work piece holder provides improved work piece quality and extended service life generally between a factor of approximately two and approximately five times, due to chemical resistance of the chemical agents used. In other words, not only can more tightly controlled flatness tolerances be achieved, but these more tightly controlled flatness tolerances can be achieved for increased durations before corrective measures (i.e., maintenance) are required.

In exemplary embodiments, the polymer layer can have specific or predetermined thermal, chemical resistance, and physical compliance properties required for a tightly controlled, high quality end-user specific polishing process. Additionally, use of polymer film results in elimination of back staining that can occur during use of Polyurethane® or Felt-based materials during the polishing process.

In exemplary embodiments, the polymer layer can be produced by skiving, extruding or casting.

It has been found that providing work piece holders having permanently affixed polymer layers or films provided to users having polishing machinery results in tighter pocket depth tolerances, as compared to depth tolerances that are achieved from work piece holders having field installed and inserted pads, which can introduce operator-induced dimensional variations.

Additional benefits associated with the use of polymer film materials is that the population of materials, sometimes referred to as pad materials or pads, can be incorporated into a “fixed” template or work piece holder without having to be concerned with pad porosity versus adhesive volume, which can impact variation between work piece holder cavities and overall work piece quality achieved in the polishing process. Pad porosity is primarily concerned with the open volume of the pad which must be filled to create a seal sufficient to control slurry intrusion. Slurry intrusion eventually creates back staining, which can be difficult to remove, and is undesirable for workpieces being processed.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. 

What is claimed is:
 1. A work piece holder for use in a polishing machine, the work piece holder having a frame composed of a thermoset material and/or a thermoplastic material, the frame having at least one cavity for receiving and supporting a work piece to be polished in the polishing machine, a polymer film being permanently affixed in the at least one cavity.
 2. The work piece holder of claim 1, wherein the polymer film is produced by skiving, extruding or casting.
 3. The work piece holder of claim 1, wherein the frame comprises a first frame portion and a second frame portion, the first frame portion having at least one through opening formed therein.
 4. The work piece holder of claim 1, wherein the polymer film and frame are adapted to withstand an operating environment having a pH<5 and a pH>9.
 5. The work piece holder of claim 1, wherein the polymer film results in elimination of back staining during operation of the polishing machine.
 6. The work piece holder of claim 1, wherein the frame is visually transparent. The work piece holder of claim 1, wherein the at least one cavity having an open end and a closed end, the polymer film permanently affixed to the closed end.
 8. The work piece holder of claim 7, wherein the at least one cavity defining a counterbore.
 9. A work piece holder for use in a polishing machine, the work piece holder having a frame composed of a thermoset material and/or a thermoplastic material, the frame having at least one cavity for receiving and supporting a work piece to be polished in the polishing machine, a polymer film being permanently affixed in the at least one cavity, wherein the frame comprises a first frame portion and a second frame portion, the first frame portion having at least one through opening formed therein.
 10. The work piece holder of claim 9, wherein the polymer film and frame are adapted to withstand an operating environment having a pH<5 and a pH>9.
 11. The work piece holder of claim 9, wherein the polymer film results in elimination of back staining during operation of the polishing machine.
 12. The work piece holder of claim 9, wherein the frame is visually transparent.
 13. The work piece holder of claim 9, wherein the at least one cavity having an open end and a closed end, the polymer film permanently affixed to the closed end.
 14. The work piece holder of claim 13, wherein the at least one cavity defining a counterbore. 